Simulation games which place a viewpoint in a position within a virtual space and display a virtual image composed from that viewpoint are well known. With such games, objects are arranged within a virtual space and a virtual image of objects from the viewpoint is derived and displayed based on the distance from the viewpoint to the object, the direction, and so on, thus creating a sense of reality as though the user were within the virtual space.
To further heighten the sense of reality of the virtual space, it is desirable to simulate sound effects in addition to such visual effects. For example, in Patent Literature 1, a three-dimensional game device for composing a virtual image and game sounds from the viewpoint inside the virtual space is disclosed. The game device can thus, based on the distance between a moving body traveling through the virtual space (for example, a vehicle) and a fixed object (for example, a wall along a road) and the speed of the moving body, change the virtual reflected sound from the fixed object. For example, when uniform walls are present on both left and right sides in the direction of travel of the vehicle, the reflected sound of the engine sound, etc., from the left-side wall is made relatively louder as the left-side wall is approached, and the reflected sound of the engine sound, etc., from the right-side wall is made relatively louder as the right-side wall is approached, based on the distance from the walls and the speed of the vehicle. Also, the greater the speed of the vehicle, the louder the sound is made reflected from the side wall.    Patent Literature 1: Japanese Patent No. 3123957